John Moynahan, A-bomb Worker

STAMFORD, CONN. — John Moynahan, who was awarded the Bronze Star for his work on the Manhattan Project and accompanied an airplane that dropped an atomic bomb on Japan, has died at the age of 73.

Mr. Moynahan died at his Stamford home on Tuesday. The cause of death had not been determined, and an autopsy was planned, his widow, Mary, said Wednesday.

During his U.S. Army career, Mr. Moynahan was assistant to Gen. Leslie Groves, director of the Manhattan Project, America`s secret mission to build the atomic bomb before Germany.

Mrs. Moynahan said her husband had wondered whether his close association with that project was responsible for health problems he had in later life. He had prostate cancer that spread to the bone marrow and suffered skin cancer for years, she said.

``There is a picture in his book Atomic Diary with him bending over and touching the ground where the blast had taken place in New Mexico, that he had sent to the Veterans Administration to show how close to the blast he had been,`` she said.

``The Veterans Administration said his skin cancer had come from the sun and was a result of his Irish skin type.

``But he had other forms of cancer in addition to skin cancer. That was a copout on the part of the Veterans Administration.``

Begun in August 1942, the Manhattan Project culminated three years later in the bombing of Hiroshima and Nagasaki.

Mr. Moynahan was one of the first to witness the effects of atomic power at tests in Alamagordo, N.M.